stats: Break out from tc.c

Maybe this can be reused for other things.

Signed-off-by: Casper Andersson <[email protected]>

CMakeLists.txt

@@ -19,7 +19,7 @@ project(tstest VERSION 1.0)
 
 # ---- BUILD ----
 add_executable(tstest)
-target_sources(tstest PRIVATE src/liblink.c src/timestamping.c src/ptp_message.c src/extts.c src/pkt.c src/tstest.c src/delay.c src/check.c src/tc.c)
+target_sources(tstest PRIVATE src/liblink.c src/timestamping.c src/ptp_message.c src/extts.c src/pkt.c src/tstest.c src/delay.c src/check.c src/tc.c src/stats.c)
 
 target_include_directories(tstest PUBLIC ${PROJECT_INCLUDES})
 target_link_libraries(tstest PUBLIC)

include/stats.h

@@ -0,0 +1,37 @@
+// SPDX-License-Identifier: GPL-2.0-only
+// SPDX-FileCopyrightText: 2024 Casper Andersson <[email protected]>
+
+#ifndef __STATS_H__
+#define __STATS_H__
+
+#include <inttypes.h>
+
+typedef struct {
+	int64_t mean;
+	int64_t max;
+	int64_t min;
+} Result;
+
+/* Ingress/egress latency of host should be accounted for in these timestamps */
+struct tsinfo {
+	uint16_t seqid;
+	int64_t tx_ts;
+	int64_t rx_ts;
+	int64_t correction;
+};
+
+typedef struct {
+	int count;
+	int size;
+	struct tsinfo *tsinfo;
+} Stats;
+
+int init_stats(Stats *s, int size);
+void free_stats(Stats *s);
+int add_stats(Stats *s, int64_t tx_ts, int64_t rx_ts, int64_t correction, uint16_t seqid);
+Result stats_get_time_error(Stats *s);
+Result stats_get_latency(Stats *s);
+Result stats_get_pdv(Stats *s);
+void show_stats(Stats *s, char *p1, char *p2, int count_left);
+
+#endif /* __STATS_H__ */

src/stats.c

@@ -0,0 +1,174 @@
+// SPDX-License-Identifier: GPL-2.0-only
+// SPDX-FileCopyrightText: 2024 Casper Andersson <[email protected]>
+
+#include <inttypes.h>
+#include <errno.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <linux/if_ether.h>
+
+#include "liblink.h"
+#include "stats.h"
+
+/* TODO:
+ * - If performance becomes slow, aggregate all calculations into one
+     loop and return a struct with all results.
+ */
+
+int init_stats(Stats *s, int size)
+{
+	if (size == 0)
+		s->size = 100;
+	else
+		s->size = size;
+	s->count = 0;
+	s->tsinfo = malloc(sizeof(struct tsinfo) * s->size);
+	if (!s->tsinfo) {
+		ERR("failed to allocate stats array");
+		return ENOMEM;
+	}
+	return 0;
+}
+
+void free_stats(Stats *s)
+{
+	free(s->tsinfo);
+	s->tsinfo = NULL;
+}
+
+int add_stats(Stats *s, int64_t tx_ts, int64_t rx_ts, int64_t correction, uint16_t seqid)
+{
+	if (s->count == s->size) {
+		s->size = s->size * 2;
+		s->tsinfo = realloc(s->tsinfo, sizeof(struct tsinfo) * s->size);
+		if (!s->tsinfo) {
+			ERR("failed to reallocate stats array");
+			return ENOMEM;
+		}
+	}
+
+	s->tsinfo[s->count].seqid = seqid;
+	s->tsinfo[s->count].tx_ts = tx_ts;
+	s->tsinfo[s->count].rx_ts = rx_ts;
+	s->tsinfo[s->count].correction = correction;
+	s->count++;
+	return 0;
+}
+
+static int64_t tsinfo_get_error(struct tsinfo tsinfo)
+{
+	return tsinfo.rx_ts - tsinfo.tx_ts - tsinfo.correction;
+}
+
+static int64_t tsinfo_get_latency(struct tsinfo tsinfo)
+{
+	return tsinfo.rx_ts - tsinfo.tx_ts;
+}
+
+Result stats_get_time_error(Stats *s)
+{
+	int64_t sum_err = 0;
+	int64_t timeerror;
+	Result r;
+
+	timeerror = tsinfo_get_error(s->tsinfo[0]);
+	r.max = timeerror;
+	r.min = timeerror;
+	for (int i = 0; i < s->count; i++) {
+		timeerror = tsinfo_get_error(s->tsinfo[i]);
+		if (timeerror > r.max)
+			r.max = timeerror;
+		if (timeerror < r.min)
+			r.min = timeerror;
+		sum_err += timeerror;
+	}
+	r.mean = sum_err / s->count;
+	return r;
+}
+
+Result stats_get_latency(Stats *s)
+{
+	int64_t sum_lat = 0;
+	int64_t latency;
+	Result r;
+
+	latency = tsinfo_get_latency(s->tsinfo[0]);
+	r.max = latency;
+	r.min = latency;
+	for (int i = 0; i < s->count; i++) {
+		latency = tsinfo_get_latency(s->tsinfo[i]);
+		if (latency > r.max)
+			r.max = latency;
+		if (latency < r.min)
+			r.min = latency;
+		sum_lat += latency;
+	}
+
+	r.mean = sum_lat / s->count;
+	return r;
+}
+
+static int64_t pdv_get_lucky_packet(Stats *s)
+{
+	int64_t lucky_packet, tmp;
+
+	lucky_packet = s->tsinfo[0].rx_ts - s->tsinfo[0].tx_ts;
+	for (int i = 1; i < s->count; i++) {
+		tmp = s->tsinfo[i].rx_ts - s->tsinfo[i].tx_ts;
+		if (tmp < lucky_packet)
+			lucky_packet = tmp;
+	}
+	return lucky_packet;
+}
+
+Result stats_get_pdv(Stats *s)
+{
+	int64_t lucky_packet, tmp, sum = 0;
+	Result r = { 0 };
+
+	lucky_packet = pdv_get_lucky_packet(s);
+	r.max = 0;
+	r.min = 0;
+	for (int i = 0; i < s->count; i++) {
+		tmp = (s->tsinfo[i].rx_ts - s->tsinfo[i].tx_ts) - lucky_packet;
+		sum += tmp;
+		if (tmp > r.max)
+			r.max = tmp;
+	}
+	r.mean = sum / s->count;
+	return r;
+}
+
+void show_stats(Stats *s, char *p1, char *p2, int count_left)
+{
+	if (s->count == 0) {
+		printf("No measurements\n");
+		return;
+	}
+
+	printf("===============\n");
+	if (count_left)
+		printf("%d measurements (exited early, expected %d)\n", s->count,
+		       s->count + count_left);
+	else
+		printf("%d measurements\n", s->count);
+	printf("%s -> %s\n", p1, p2);
+
+	Result time_error = stats_get_time_error(s);
+	Result latency = stats_get_latency(s);
+	Result pdv = stats_get_pdv(s);
+
+	printf("--- TIME ERROR ---\n");
+	printf("Mean: %" PRId64 "\n", time_error.mean);
+	printf("Max : %" PRId64 "\n", time_error.max);
+	printf("Min : %" PRId64 "\n", time_error.min);
+	printf("--- LATENCY ---\n");
+	printf("Mean: %" PRId64 "\n", latency.mean);
+	printf("Max : %" PRId64 "\n", latency.max);
+	printf("Min : %" PRId64 "\n", latency.min);
+	printf("--- PDV ---\n");
+	printf("Mean: %" PRId64 "\n", pdv.mean);
+	printf("Max : %" PRId64 "\n", pdv.max);
+	printf("Min : %" PRId64 " (lucky packet)\n", pdv.min);
+	printf("===============\n");
+}

src/tc.c

@@ -11,7 +11,6 @@
 #include <sys/types.h>
 #include <unistd.h>
 #include <signal.h>
-#include <pthread.h>
 #include <inttypes.h>
 
 #include "net_tstamp_cpy.h"
@@ -20,6 +19,7 @@
 #include "liblink.h"
 #include "tstest.h"
 #include "pkt.h"
+#include "stats.h"
 
 /* Measure the one-way inaccuracy through a TC. Runs on two ports that
  * are either synchronized or use the same PHC. The inaccuracies will
@@ -138,122 +138,6 @@ static void send_pkt(struct pkt_cfg *cfg, int sock, int64_t *tx_ts)
 	}
 }
 
-/* Ingress/egress latency of host should be accounted for in these timestamps */
-struct tsinfo {
-	uint16_t seqid;
-	int64_t tx_ts;
-	int64_t rx_ts;
-	int64_t correction;
-};
-
-typedef struct {
-	int count;
-	int size;
-	struct tsinfo *tsinfo;
-} Stats;
-
-static int init_stats(Stats *s, int size)
-{
-	if (size == 0)
-		s->size = 100;
-	else
-		s->size = size;
-	s->count = 0;
-	s->tsinfo = malloc(sizeof(struct tsinfo) * s->size);
-	if (!s->tsinfo) {
-		ERR("failed to allocate stats array");
-		return ENOMEM;
-	}
-	return 0;
-}
-
-static void free_stats(Stats *s)
-{
-	free(s->tsinfo);
-}
-
-static int add_stats(Stats *s, int64_t tx_ts, int64_t rx_ts, int64_t correction, uint16_t seqid)
-{
-	if (s->count == s->size) {
-		s->size = s->size * 2;
-		s->tsinfo = realloc(s->tsinfo, sizeof(struct tsinfo) * s->size);
-		if (!s->tsinfo) {
-			ERR("failed to reallocate stats array");
-			return ENOMEM;
-		}
-	}
-
-	s->tsinfo[s->count].seqid = seqid;
-	s->tsinfo[s->count].tx_ts = tx_ts;
-	s->tsinfo[s->count].rx_ts = rx_ts;
-	s->tsinfo[s->count].correction = correction;
-	s->count++;
-	return 0;
-}
-
-static int64_t tsinfo_get_error(struct tsinfo tsinfo)
-{
-	return tsinfo.rx_ts - tsinfo.tx_ts - tsinfo.correction;
-}
-
-static int64_t tsinfo_get_latency(struct tsinfo tsinfo)
-{
-	return tsinfo.rx_ts - tsinfo.tx_ts;
-}
-
-static void show_stats(Stats *s, char *p1, char *p2, int count_left)
-{
-	int64_t max_err, min_err, sum_err = 0;
-	int64_t max_lat, min_lat, sum_lat = 0;
-	int64_t timeerror, latency;
-
-	if (s->count == 0) {
-		printf("No measurements\n");
-		return;
-	}
-
-	printf("===============\n");
-	if (count_left)
-		printf("%d measurements (exited early, expected %d)\n", s->count,
-		       s->count + count_left);
-	else
-		printf("%d measurements\n", s->count);
-	printf("%s -> %s\n", p1, p2);
-
-	timeerror = tsinfo_get_error(s->tsinfo[0]);
-	latency = tsinfo_get_latency(s->tsinfo[0]);
-	max_err = timeerror;
-	min_err = timeerror;
-	max_lat = latency;
-	min_lat = latency;
-
-	for (int i = 0; i < s->count; i++) {
-		timeerror = tsinfo_get_error(s->tsinfo[i]);
-		latency = tsinfo_get_latency(s->tsinfo[i]);
-		if (timeerror > max_err)
-			max_err = timeerror;
-		if (timeerror < min_err)
-			min_err = timeerror;
-		sum_err += timeerror;
-
-		if (latency > max_lat)
-			max_lat = latency;
-		if (latency < min_lat)
-			min_lat = latency;
-		sum_lat += latency;
-	}
-
-	printf("--- TIME ERROR ---\n");
-	printf("Mean: %" PRId64 "\n", sum_err / s->count);
-	printf("Max : %" PRId64 "\n", max_err);
-	printf("Min : %" PRId64 "\n", min_err);
-	printf("--- LATENCY ---\n");
-	printf("Mean: %" PRId64 "\n", sum_lat / s->count);
-	printf("Max : %" PRId64 "\n", max_lat);
-	printf("Min : %" PRId64 "\n", min_lat);
-	printf("===============\n");
-}
-
 static void run(struct pkt_cfg *cfg, char *p1, char *p2, int p1_sock, int p2_sock)
 {
 	int64_t rx_ts, tx_ts, correction, total_err;